The purpose of the Addendum is to provide additional information to the public regarding the potential environmental impacts of unconventional natural gas exploration and production activities. DOE has received many comments related to concerns about the potential impacts from increased development of unconventional natural gas resources in the US, particularly production that involves hydraulic fracturing. While not required by the National Environmental Policy Act (NEPA), DOE has prepared this Addendum in an effort to be responsive to the public and provide the most current information available.

The Addendum is intended to provide information only on the impact areas most often associated with unconventional natural gas production. The Addendum is not the result of new analysis or research, but rather is based on DOE’s review of existing studies and analyses. A key resource in preparing the Addendum was the report Environmental Impacts of Unconventional Natural Gas Development and Production (May 29, 2014), prepared by the National Energy Technology Laboratory, a DOE Laboratory.